1. Field of the Invention
The present invention relates to an image forming system handling image data and, more specifically, to an image forming system having a use restriction function for a user.
2. Description of the Background Art
Currently, image forming apparatuses such as digital copy machines and printers are very common everywhere and indispensable at worksites using computers. Recently, image forming apparatuses having color-printing function are also increased and in widespread use.
At the same time, abuse such as private use other than for business purpose comes to pose a problem. Abuse is problematic because it is difficult to identify who did it, and because it is hard to keep a close check on private use, which is often made after business hours. Abuse of color printing is particularly a big problem, as its unit cost is high and use other than business purpose incurs burden of expense.
In connection with this problem, Japanese Patent Laying-Open No. 2003-348279 (hereinafter referred to as “'279 application”) discloses a technique of imposing use restriction user by user, in which if one makes an attempt to use an image forming apparatus during off-hours, a warning display appears and the operation is stopped. According to the technique disclosed in '279 application, in the image forming apparatus, a user ID, a function or functions (including color-copying function) permitted for each user ID, available hours for the permitted functions, available hours of the image forming apparatus itself and so on are registered beforehand. The image forming apparatus receives an input of user ID, and performs user authentication and function restriction user by user. If one tries to use the image forming apparatus during off-hours, a warning display is given and the operation is stopped.
The technique of '279 stops operation and, if use is necessary before or after available hours, one must request an administrator for a change of permitted hours in advance and have the hours changed accordingly. This leads to another problem that emergency use of the apparatus at night or on holidays is impossible.
In this regard, Japanese Patent Laying-Open No. 2007-230013 (hereinafter referred to as “'013 application”) discloses a technique directed to an image forming apparatus in which even when print restriction is set in advance for each user, the print restriction is cancelled temporarily by a user operation to allow printing.
Further, management of documents to be printed is also a major security concern.
Japanese Patent Laying-Open No. 2007-160889 (hereinafter referred to as “'889 application”) discloses a technique of issuing a one-time password valid for only one print job. By inputting the issued password, a user can obtain output of a designated print job. The issued one-time password is valid only for one print job designated by the user and, even if the password is leaked or lost after the end of printing, printing of the document can be prevented. As a result, ill-intentioned printing resulting from password leakage can be prevented.
From the viewpoint of preventing abuse of image forming apparatus, the technique of user authentication and setting of available time for permitting use is effective. Restricting the use of image forming apparatus only by time, however, is in many regards disadvantageous, considering business after hours at offices. Particularly, if the user is trying hard to meet the deadline and the image forming apparatus should become unavailable just before the finish, it would significantly affect the business. Therefore, it is an important issue to prevent private use of the image forming apparatus while not negatively affecting business operations.
In the technique disclosed in '279 application, for use before or after hours, one must ask an administrator to change the available time. Therefore, it is inadequate in case of emergency at night or on a holiday, and it cannot solve the problem.
The technique disclosed in '013 application temporarily cancels print restriction in response to an operation by the user. This technique, however, allows cancellation of use restriction also at the time of non-emergency, which means that abuse is possible. Thus, it cannot solve the problem.
Further, private use of the image forming apparatus possibly leads to leakage of information to the outside. Prevention of private use is, therefore, a serious issue also from the viewpoint of information management.
The technique disclosed in '889 application is directed to issuance of a password for printing a document and, therefore, it cannot solve problems related to document and information management.